Wrapper feeding mechanism



April 3, 1934. E. SMITH El AL WRAPPER FEEDING MECHANISM Sheets-Sheet 1 Filed March 21 1932 INVENTORS Mum/v [lb/ P:

* AT ORNEYS.

April 3, 1934. sMlTH ET AL 1,953,196

WRAPPER FEEDING MECHANISM Fil'ed March 21, 1932 2 Sheets-Sheet 2 INVENTORS iZ/m? Z. J/v/m Mo y Mum/v JYOPP:

Patented Apr. 3, 1934 WRAPPER FEEDING MECHANISM 1 Elmer .L. Smith,- Longmeadow, and William,

Hoppe, Springfield, Mass, assignors to National Bread Wrapping Machine Company, Springfield, Mass., a corporation of Massachusetts Application March 21,

17 Claims.

This invention relates to machines for feeding a web of paper or other material and for severing sheets therefrom "and delivering them to a predetermined location. One object of the invention is to improve prior devices of this character in respect to their speed, smoothness of oporation, and simplicity of construction. Another object is'to provide a mechanism employing a series of continuously moving grippers which pick up without substantial strain the leading end of a stationary web, draw out the web until a sheet is severed therefrom, and finally position the severed sheet in a predetermined position. Another. object is to provide an improved mechanism to produce slack in the web so that its leading end can be picked up by the grippers without und-ue strain. Additional objects will appear from the following description and claims.

The present application is a continuation in part of our priorapplication Serial No. 592,250,

filed February "11,. 1932.

Referring to the drawings:

Fig. 1 is a section through a paper feeding mechanism made in accordance with this invention; Figs. 2 and 3 are similar views illustrating certain of'the parts in difi'erent positions of operation; I

Fig. 4 isan enlargement of a part of Fig. 2; Fig. 5 is a detail of one of the paper grippers,

' taken on an enlarged scale;

Fig. 6 is an enlargeddetailof a portion of Fig. 1;

Fig. 7 is a similar detail showing the parts in a dilferent position of operation; and

Figs. 8, 9 and 10 are sectional details of the gripper shown in Fig. 5, showing successive stages in its operation.

A roll 11 of paper or other wrapping material is mounted on a suitable support 12 (Fig. 1). From the roll the web 10 passes under a guide roll 13 adjustably mounted in slots 14' in spaced frame members 15, only one of which appears in the drawings. The web then passes around a continuously rotating snubbing roll 16, carried by a shaft 17 and preferably having its surface 00V,- ered with canvas or other friction material. While the snubbing roll is in continuous rotation, it operates to feed the web w from the roll- 11 only when the web is held under tension by other mechanism to be described. From thesnubbing rollthe web passes first .under a floating roll 18, mountedin slanting guideways 19 and normally held in the position of Fig. 1 by a spring 20, and finally over the top of a table 21.

1932, Serial No. 600,294

Positioned to rest upon the web lying on the table 21 is a hold back roll 22 (Fig. 6) carried upon the free ends of arms 23 pivoted at 24 to the frame. This roll is intermittently clamped by mechanism to be described to hold the web against retrograde movement. A pair of knife carrying arms 25 and 26 are pivoted at a common point 2'7 and bear respectively knives 28 and 29 positioned when the arms are swung together to sever the web at a point slightly beyond the end of'the table 21. This construction is desirable since'the motion of the knife parts in opposite directions doubles their effective speed and balances t e inertia of the parts. For the purpose of des ribing the operation of the web forwarding grippers, the web may be considered initially as extending slightly beyond the end of the table in the manner shown in Figs. 1 and 6.

The projecting end of the web is grasped by one of aseries of grippers mounted upon chains 30 which move continuously during the operation of the machine. These chains each pass around a driving sprocket 31 on a shaft 32, an adjustable sprocket 33, and a pair of idle sprockets 34 and 35. The grippers are generically indicated at 36. Three grippers are shown in the preferred form, spaced equally along the chains. Each gripper is carried by one side of an angle iron 37, extending between the chains and secured to them as shown in Fig. 5, and carrying spaced "bearings 38 for the cylindrical bearing portions of an otherwise square bar 39. A second angle iron 40 is secured to the square bar forming the movable member of the gripper, of which the angle 37 forms the fixed member. Spring fingers 41 may be secured along one side of the angle" and project slightly beyond it; the fingers serving, when used, to press the paper against the end of the relatively stationary gripper member 37 as shown in Fig. 9. If desired, the angle irons 3'7 and 40 may be faced with canvas or may have their frictional characteristics otherwise increased to enhance the positiveness of their hold on the paper.

The grippers are normally held closed, or in the position of Fig. 9, by springs 42 stretched between pins 43 on'the'square shaft 39 and a plate 44 secured to the stationary angle 37. In theirpaper gripping and releasing positions the grippers are positively opened during the continuous motion of the chains by stationary cam plates operating against a roll 45 carried on an plate 48 serves as shown in Figs. 1 and 10. In both positions the stationary angle 37 is guided by fixed rails 49 so that the gripper is under positive control. The cam plates are preferably secured to the frame by slotted connections, as indicated in Fig. 8, so as to permit of slight adjustment. This adjustment when once set is not ordinarily disturbed, the grippers opening and closing in constant timed relation to the machine to which the cut sheet is delivered.

The coaction between the grippers 36 and the remaining feeding and cutting mechanism will now be described. The leading edge of the paper web w has been fed out in the previous cycle so that it projects slightly beyond the support 21. A gripper 36 is carried upwardly along the guide 49 as shown in Fig. 8, its roll snapping off the edge of cam 47 (Fig. 9) just as the gripping member 40 comes into position overlying the end of the paper. As the gripper closes the leading end of the web is bent around the edge of the stationary gripper member, and is pressed against the end of this member by the fingers 41 and against its inner surface by the end of the angle iron 40. This gripping action extends through the entire width of the web and due to this and also to the bending over of the paper end gives a very firm hold.

It will be noted that at the time when the web is seized by the grippers the latter are moving vertically upwardly so that they have a relatively slight pulling effect on the paper. The grippers immediately begin their travel around the adjacent sprockets 35, giving to the web an acceleration from a state of rest up to a speed equal to the linear speed of the chains 30 when the gripper has reached its horizontal run. This action of the grippers is of great importance, as the strain on the web in starting its motion is greatly reduced. The absence of strain is also brought about by the slackness of the web, as will be described in detail below.

As the grippers continue with the severed wrapper sheet s a clamp descends upon it so as to exert a drag against the rear end of the sheet when the grippers release it. When this occurs the sheet remains suspended in front of the sheet treating mechanism, in this case indicated as the article receiving pocket 51 of a wrapping mecha-- nism. The clamp is carried on a shaft 52 which also, carries an arm 53 hearing at its end a cam roll 54 running on acam 55 on a rotating shaft 56. A suitable spring (not shown) draws the arm against the cam, so that a yielding pressure of the clamp against the underlying paper supporting table 57 is secured. The manner in which the sheet is moved into the carrier from its suspended position is not material to an understanding of the present invention and will not be described.

Ona shaft 60 is placed a cam 61. A lever 62 is pivoted to the frame 15 and; bears a roll 63 held against the cam by a spring 64. The knife carrying arm 25 is coupled to lever 62 by a link 65, and the rear end of arm 26 is similarly connected by a link 66. Thus as the cam 61 rotates, the knife members 28 and v 29 will be moved past each other from the position of Fig. 6 to that of Fig. 7. The blade 28 is preferably serrated so as to form a series of perforations extending entirely across the sheet, the knives making contact with the web substantially simultaneously across its entire width.

The hold back roll 22 is, as stated above, mounted on arms 23 swinging freely on a pivot shaft 24. A brake arm on this shaft is drawn downwardly by a spring 71, carrying a brake member 72 adapted to bear on the roll 22 and also an abutment 73. Upon the lever 26 is mounted a cam piece 74 adapted to contact with the abutment 73, so that when the parts are in the position of Fig. 6 the brake member is raised off the roll and when the knife makes its out the roll is clamped as shown in Fig. 7. The brake prevents any slipping back of the web and also exertsaslight drag on the web at the instant of out which assists the operation of the knife.

The operation of the device taken as a whole .will now be considered. As the moving gripper picks up the leading end 'of the web w the latter is in the condition shown in Fig. 1. 1 The brake '72 is ofl the hold back roll 22 and the web ,is slack below the roll 18. The gripper thus picks up the web free from any tension other than the relatively insignificant weight of the web suspended between the plate 21 and the tension roll 18. During the initial part of the movement of the roll this same condition continues, the gripper passing around the guide sprockets 35 without encountering any substantial resistance. When it has passed around these sprockets it has turned through an angle of substantially 90, and the web is drawn around three sides of the stationary part of the gripper as shown in Fig. 4. The added grip thus given on the paper prevents slippage when' the slack of the web is ultimately exhausted and the gripper is forced to pull the web around the take up roll 18.

When this state is reached, the web raises the roll 18 against the tension of its spring 20 and draws itself tightly around the surface of the constantly rotating snubbing roll 16. The web extends around the circumference of this roll in an arc determinable by the adjustment of roll 13, and when it is pulled tightly causes the roll to exert a feeding tension upon it by which it is unwound from the supply roll 11. The snubbing roll 16 is driven in a constant timed relation with shafts 60 and 32 by chains 75, 76, preferably at a surface speed slightly higher than the linear speed of the grippers so that while it is acting it tends to feed the web at a speed which will permit the take up roll 18 to descend slowly.

At the instant of cut (Fig. 3) the web is clamped to the table 21 by the brake 72 acting on the hold back roll 22, and the forwardmovement of the leading end of the web is thus interrupted while the severed sheet is carried away by the grippers. The cutting action of the blades 28, 29 is thus assistedby the tendency of the web to be pulled apart by the gripper on one side and the hold back roll on the other. The snubber roll continues its rotation, feeding from the supply roll until the tension of spring 20 is'relieved by the delivery of sumcient slack to permit the roll 18 to descend to the bottom of its" guiding groove. Although the feeding action of the snubbing roll then stops due to the cessation of frictional contact of the paper with it, the roll 11 is in rotation at a considerable speed and continues until it is stopped by its own friction. The short overrun thus obtained is sufficient to provide slack in the web-for the next cycle.

The invention has been described in considerable detail in the interest of clearness. It will be understood, however, that numerous changes .might be made in the structure disclosed while adhering to the principles of the invention as defined in the following claims. For example, while three grippers are described as being mounted in series on the conveyor chains, a single gripper could be used, or a diflferent number employed in the series, depending upon the timing of. the mechanism to which the out sheets are delivered. Other modifications to'adapt the invention to dif- 5 ferent environments will occur to those skilled in the art.

What we claim is:

1. Web feeding and cutting mechanism comprising means for supporting the leading'end of a continuous web, a gripper moving continuously in an endless path passing the stationary web at a substantial angle, means for closing the moving gripper upon the leading end of the stationary web while the gripper is in the angular portion of its pathand is moving in a direction'transverse to the plane of said leading end, a cutter operating to sever a sheet from the web being forwarded by the gripper, and means for opening th gripper to release the severed sheet.

2.'Web feeding and cutting mechanism comprising means for supporting the leading end of a continuous web, a gripper moving continuously in a closed path having a portion passing the stationary web at substantially right ,anglesand thereupon curving towards a direction parallel to that of the web, means for closing the moving gripper upon the leading end of the stationary web while the gripper is in the angular portion of its path and is moving in a direction transverse to the plane of said leading end, a cutter operating to sever a sheet from the web being,

forwarded by the gripper, and means for opening the gripper to release the severed sheet.

.3. Web feeding and cutting mechanism comprising means for supporting the leading end of a continuous web, a gripper moving continuously in an endless path passing the stationary web at a substantial angle, means for closing the moving gripper upon the leading end of the stationary web while the gripper is in the angular portion of its path, a pair of coacting cutters swinging on axes parallel to the cutting edges of the cutters, means for swinging the cutters in timed relation with the grippers either to a cutting position where they severe a sheet from the web being forwarded by the grippers or to an inactive position where they do not interfere with the grasping of the leading end of the web by the grippers, and means for opening the'grippers to release a severed sheet.

4. Web feeding and cutting mechanism 'comprising means for supporting the leading end of a continuous web, a gripper moving in an endless path, said path having an angle adjacent the web and a straight portien extending in substantially the line of the web, means for closing the moving gripper upon the leading end of the stationary web as the gripper starts its motion through said angle, whereby the gripper will impart a steady acceleration .to theweb as the gripper moves into the straight portion of the path, a cutter operable to severe a sheet from the web being forwarded by the gripper, and means for opening the gripper to release the severed sheet.

5. Web feeding and cutting mechanism comprising means for supporting the leading end of a continuous web, a pair of conveyors, one on each side of the web, moving continuously in a closed path, a gripper extending between the conveyors means for opening the gripper to release the severed sheet.

6. Web feeding and cutting mechanism comprising means for supporting the leading end of a continuous web, a gripper extending across substantially the entire width of the web and moving continuously in an endless path, said gripper having an angular web contacting portion so that the end of the web will be bent over at an abrupt angle when the gripper is closed upon it, means for closing the moving gripper upon the "leading end of the stationary web, a cutter operating to sever a sheet from the web being forwarded by the gripper, and means for opening the gripper to release the severed sheet.

7. Web feeding and cutting mechanismcomprising means for supporting the leading end of a continuous web, a pair of endless chains one at each side of the web path, a gripper extending between the chains and having coacting members adapted to grasp the leading end of the web substantially throughout its width, supporting and driving sprockets for the chains arranged to direct them in parallel paths, one pair of the sprockets being positioned adjacent the leading end of the web so that the gripper will approach the web at substantially right angles to it and will thereupon turn into a direction substantially in line with the web, means for driving the chains continuously, means for closing the gripper upon the leading end of the web, a cutter operating to sever a sheet from the web being forwarded by the gripper, and means for opening the gripper to release the severed sheet.

8. Web feeding and cutting mechanism comprising a web supply roll, a constantly rotating snubbing roll around which the web is led, a web feeding gripper adapted to seize the leading end of the web while the web is under substantially no tension, continued motion of the gripper resulting in drawing the web around the snubbing roll so as to be fed by the latter from the supply roll, and means for severing a sheet from the drawn out web.

9. Web feeding and cutting mechanism comprising a web supply roll, a constantly rotating snubbing roll around which the web is led, a gripper moving with a continuous motion in an endless path, means for closing the gripper upon the leading end of the web while the latter is under substantially no tension, continued motion of the gripper resulting in drawing the web around the snubbing roll so as to be fed by the latter from the supply roll, means for severing a sheet from the web while in motion, and means for opening the gripper to release thesevered sheet.

10. Web feeding and cutting mechanism comprising a web supply roll, a constantly rotating snubbing roll around which the web is led, a gripper moving with a continuous motion in an endless path, means for preventing retrograde movement of the leading end of the web, means for closing the gripper upon. the leading end of the web while the latter is under substantially no tension, continued motion of the gripper resulting in drawing the web around the snubbing roll so as to be fed by the latter, means for severing a sheet from the web while in motion, and means for opening the gripper to release the severed sheet.

11. Web feeding and cutting mechanism comprising a web supply roll, a continuously rotat- ,v

snubbing roll, a web supporting means, a device acting in conjunction with said means for preventing retrograde movement of the web, a slack takeup roll positioned between the snubbing roll and the web supporting means and having its slack take-upmovement limited in amount, a gripper engaging the leading end of the web held on the supporting means and movable to draw out the web, first drawing against the take-up roll and then drawing the web against the snubbing roll so as to be fed by the latter, and means for severing a sheet from the web drawn out by the gripper.

12'. Web feeding and cutting mechanism comprising a web supply, a support across which the webQpasses from said supply, a pair of cutter members pivoted upon axes extending across the web, means for swinging the cutter members simultaneously in opposite directions so that their cutting edges pass at the plane of the web and at a point beyond the end of said support, and

means for drawing out the leading end of the web. g

13. Web feeding and cutting mechanism comprising a web supply, a support across which the web ,passes from said supply, a pair of cutter members pivoted upon axes extending across the web, means for swinging the cutter members simultaneously in opposite directions so that their cutting edges pass at the plane of the web and at a point beyond the end of said support, a roll resting upon the web above the support, a clamp adapted to restrict rotation of said roll, connections between the clamp and the means for swinging the cutter members so that the clamp is applied as the cutters are moved to sever the web, and means for drawing the leading end of the web past the cutting members.

14. Web feeding and cutting members comprising a web supply, a support across which the web passes from said supply, a pair of cutter members pivoted upon axes extending across the web, means for swinging the cutter members simultaneously in opposite directions so that their cutting edges pass at the plane of the web and at a point beyond the end of said support, a roll yieldably restingupon the web above the support, an arm carrying a brake adapted to contact with the roll to restrain its rotation and spring pressed towards the roll, acam carried by a portion of the cutter operating mechanism to' raise said arm from the roll when the cutting members are in their inactive position, andmeans for drawing the leading end of the web past the cutting members.

15.,Web feeding and cutting mechanism comprising a web supply roll, a continuously rotating snubbing roll around which the web is led, a guide roll between the supply roll and the snubbing roll, a web supporting plate, a hold back roll of the linear speed of the gripper.

.to clamp the latter when the cutting members are moved to sever the web, one or more grippers movable continuously in an endless path having an angular portion adjacent the point where the web is severed, means for closing a gripper upon the end of theweb while the gripper is moving at substantially right angles to the web, the gripper thereafter passing through the angular portion of its path to cause the web to be accelerated up to the linear speed of the grippers, the web being thereby caused to pull upon the slack take-up roll and to draw tightly upon the snubbing roll and to be fed thereby from the supply roll, means for opening the gripper to release the severed sheet, and mechanism for driving the grippers, the cutting members, and the snubbing roll in timed relation with the surface speed of the snubbing roll slightly in excess 16. An apparatus of the class described comprising means for supporting a length of material so that its leading end is accessible, a gripper movable in an endless path, the path having its portion adjacent the leading end of the'material inclined at a substantial angle to the direction of the material, and means for closing the gripper upon the leading end of the material while the gripper is traveling along the angular portion of its path and in a direction transverse to the plane of said leading end.

17.' An apparatus of the class described comprising means for supporting at rest a length of material so that its leading end is accessible, a gripper moving continuously in an endless path, the path having its portion adjacent the leading end of the material inclined at a substantial angle to the direction of the material and thereupon curving towards a direction generally parallel to that of the material, and means for closing the gripper upon the leading end of the material while the gripper is traveling along the angular portion of its path and in a direction transverse to the plane of said leading end, whereby the gripper while maintaining a substantially constant speed along its path imparts a gradually accelerated movement to the material. 

